1. Field of the Invention
The present invention relates to valve assemblies and more particularly to a valve assembly for providing a controlled pressurized flow to a device. Even more particularly, the present invention provides a configurable valve assembly having both high speed response and flow rate.
2. Description of the Prior Art
Many valves for controlling differential fluid flows and pressures have been developed. U.S. Pat. No. 4,005,733 entitled PRESSURE CONTROL VALVE teaches a valve with a pair of axially spaced inlets in fluid communication with a chamber; the chamber is, in turn, in fluid communication with a consumer which receives the pressurized fluid flow.
Pressure in, and flow through the chamber is varied by an oscillating valve member. The valve member is movable to a first position which opens a first inlet and closes a second inlet. The valve member has a second position which closes the second inlet and opens the first inlet. The valve is solenoid operated and includes the valve member which acts as the solenoid armature.
An example of a high-frequency valve is shown in U.S. Pat. No. 3,661,183 entitled ELECTROMAGNETICALLY OPERATED VALVE WITH TWO SEATS which discloses a valve having a spherical valve member, a control chamber and two seats. In this valve, the spherical valve member is disposed in the control chamber between the two seats. Movement of the valve member results (in one direction) from a force exerted by an armature. The armature extends into the control chamber and is pressed against the valve member by a spring. Thus, the spring holds the valve member against one seat. The armature is retracted to a disengaged position from the valve member by a solenoid to allow fluid pressure to float the valve member to the other seat, as does the valve shown in U.S. Pat. No. 4,005,773. Operation of this valve depends on the pressure of the fluid at one port urging the valve member into engagement with the opposing valve seat.
In U.S. Pat. No. 4,719,943, a CONTROL VALVE ASSEMBLY is disclosed wherein a poppet connected to a control arm is positionable between a first and a second position through the use of a spring and a solenoid. The poppet provides fluid flow between one of a plurality of inlets and one of a plurality of outlets in response to electrical signals transmitted to the solenoid via wiring. Electrical pulses are dispatched to the solenoid moving the poppet between a first and a second position at a high frequency.
Several problems exist with each of the above mentioned valves. First, each of the above described valves fails to provide means for high flow rate of fluid therethrough at high fluid pressure because the cross-sectional areas of the pathways adjacent to the valve member are quite large. Therefore, if one were to attempt to apply a great deal of pressure with the great surface area afforded, the valves would fail to function properly. Essentially, leakage would occur around the edges of the valve member, or the great pressure may actually move the valve member from a first to a second position, essentially holding the valve in the open state, and damaging the devices to which it is connected.
Therefore, presently, one has available only valves that operate with either a high flow rate or high pressure, but not both. When using heavy equipment, use of a valve that can withstand high pressures is essential, as many operations such as lifting the equipment require a high pressure. In just such a case, a valve having a slow fluid flow rate must be used, making such operations tedious.
Additionally, each of the above referenced patents discloses a valve which is in the "normally-closed" state. The springs included in each of the above referenced valves biases the valve member in a closed configuration. By supplying electrical energy to a magnet therein, the valve member is "pulled" in the opposite direction to "open" the valve. Normally-closed valves are generally used to ensure that if the valve fails, the valve failure will not cause other equipment to fail or be damaged. However, there is sometimes a need for the valve to be in an open configuration if the equipment fails. As such, the prior art is deficient in supplying a valve that may be configured as either a normally open valve or a normally closed valve.
It is also to be appreciated that the above referenced valves were designed for use with a liquid and not a gas. If a gas were fed through previously produced valves such as those disclosed above, it would tend to seep out of the valve at several points. Essentially, the above referenced valves were not designed to be used with a gas.
What is needed is a valve that functions at a high flow rate and at a high fluid pressure. Additionally, a valve is needed that can be used with both liquids and gasses. It would also be preferable to have a valve that could be produced in either the normally-open or the normally-closed state depending upon the application in which the valve is to be employed. It is to the solution of the above mentioned problems to which the present invention pertains.